Improvement in watches



UNIT D STATES PATENT Prion IMPROVEMENT IN WATCHES.

Specification forming part of Letters Patent No. 161,513, dated March30, 1875; application filed November 13, 1873.

To all whom it may concern:

Be it known that I, J ASONR. Horurws, of Washington city, in the countyof Washington and in the District of Columbia, have invented certain newand useful Improvements in Watches; and do hereby declare that thefollowing is a full, clear, and exact description thereof, referencebeing had to the accompa nying drawing, making a part of thisspecification, in which- Figure l is a plan view of the rear side of myimproved watch. Fig. 2 is a like view of the front side of the same, andFig. 3 is a cross-section upon line no so of Fig. 1.

Letters of like name and kind refer to like parts in each of thefigures.

In the construction of watch-movements much difficulty is experienced inso adjusting the balance-wheel as to render its motion uniform under thevarying conditions of temperature and position. This is more especiallytrue with regard to the latter, it being well known that a watch thatwill keep correct time while suspended by its ring will vary its timewhen carried about the person, which variation is caused by changes inthe position of the watch.

To remedy this liability to change in rate it is customary, in theconstruction of the line grades of watch-movements, to fix the same indifferent positions, and, after noting the time made in each, to changethe adjustment of the balance until the motion of the latterapproximates to uniformity; but as such adjustment is expensive it isapplied to comparatively few movements.

To obviate the necessity for such adjustment is the design of myinvention, which consists in a watch-movement in which the operativeparts are placed upon and revolve with a centrally-pivotedspring-barrel, and the balancewheel is pivoted at the center of suchmotion, substantially as and for the purpose hereinafter specified.

In the annexed drawing, A represents an annular metal disk, which isprovided around its inner periphery with gear-teeth a, and at its outeredge is secured to or upon one edge of the ring B, that forms thecircular portion or edge of the watch-case. Within the angle formed atthe intersection of the disk A and ring B is secured an annular piece ofmetal, 0, which nearly fills the space, laterally, between said disk andthe opposite edge of said ring, and radially extends from said ringinward to a sufficient distance to furnish bearings for two screws, (1,which are used to attach thereto the ends of a bridge, I), that extendscentrally across upon the side opposite to said disk A. Between theinner sides of the disk A and bridge D is placed a springbarrel, E,which substantially fills the space laterally and radially, and containsa central arbor, F, that passes through a suitable bearing within saidbridge, and forms an axis for and upon which said barrel revolves. Uponthe side of the barrel E opposite to the bridge D is placed a stud, g,that extends laterally outward from a point near the line of the teeth aof the disk A, and forms a bearing for a pinion, G, which meshes withsaid teeth. A toothed wheel, H, secured upon the upper end of saidpinion, meshes with the pinion i of a scapeavheel, I, which latter issuitably pivoted between said wheel H and the center of the barrel, andengages with the detent K of a chronometer escapement, while the latter,in turn, is operated by means of suitable mechanism attached to thestaff of a balance'wheel, L, that is pivoted at the center of saidbarrel. The arbor F is journaled within the barrel E, and provided uponits projecting end with a toothed ratchetwheel, 1'', that engages with aspring-pawl, f, attached to the bridge D, so that said arbor may beturned in one direction only, while within said barrel said arbor isattached to the inner end of a coiled spring, the outer end of whichlatter is attached to or upon the inner periphery of said barrel, saidarbor thus forming a windingarbor for coiling said spring, which latter,in uncoiling, turns said barrel, all in the usual manner.

As thus constructed, it will be seen that the force of the coiled springwill move the barrel, and cause the mechanism attached thereto torevolve; and that such rotary motion will be communicated through thetoothed disk to the train, so as to cause the same to operate in theusual manner, and regulate the speed with which said barrel shall move.

By means of dial-wheels the motion of the barrel may be communicated tohands, and the time indicated in the usual manner.

The principal advantage obtained by this construction is in the positionof the balancewheel, which, as seen, is placed at the center of motion,and rotates around the same, in addition to its usual vibratorymovement, the result being a constant change in the relative radialpositions of said balance and the case, which effectually prevents anydeficiency in the poise of the former from operating for any length oftime in any one direction, and thus renders uniform its movement.

In addition to the above-named advantage, the size of the balance islimited only by the size of the case, so that it becomes practicable touse a balance having such dimensions as to render the work ofcompensating and poising far more easy and certain than is possible incase of the ordinary balance.

Having thus fully set forth the nature and merits of my invention, whatI claim as new is A watch-movement in which the operative parts areplaced upon and revolve with a centrally-pivoted spring-barrel, and thebalancewheel is pivoted at the center of such motion, substantially asand for the purpose specified.

In testimony that I claim the foregoing I have hereunto set my hand this11th day of November, 1878.

J. R. HOPKINS.

Witnesses:

GEO. S. PRINDLE, Eon. F. BROWN.

